Identification and Quantification of Naphthoquinones and Other Phenolic Compounds in Leaves, Petioles, Bark, Roots, and Buds of Juglans regia L., Using HPLC-MS/MS

The present study was designed to identify and quantify the major phenolic compounds in different Juglans regia L. (common walnut) tissues (leaves, petioles, bark, roots, buds), define compositions contents of between these tissues. A total 91 individual were identified quantified, which comprised 8 hydroxycinnamic acids, 28 hydroxybenzoic 11 flavanols, 20 flavonols, 22 napthoquinones, 2 coumarins. Naphthoquinones group leaves, buds, as >60% those identified, while acids side ~50% identified. highest content J. main root, followed by roots 1-year-old bark; lowest petioles 2-year-old bark. Leaves, buds represent a valuable source agro-residues.